1. Field of the Invention
The present invention relates to a surface mounting structure and a surface mount type electronic component included in the surface mounting structure.
2. Description of Related Art
As an example of a conventional surface mount type electronic component, a piezoelectric component is known to be formed by sandwiching between two external substrates a piezoelectric substrate having an oscillation electrode disposed thereon. The external substrates define with the piezoelectric substrate an enclosed oscillation space and protects the piezoelectric substrate from mechanical stress.
In another type of known surface mounting type piezoelectric component, a piezoelectric substrate having an oscillation electrode disposed thereon is firmly attached to a base substrate, and a cover member is arranged to cover the piezoelectric substrate. The cover member defines with the base substrate an enclosed oscillation space and protects the piezoelectric substrate from external mechanical stress.
In the conventional surface mount type piezoelectric components, however, the piezoelectric resonator is covered, for example, with external substrates or a cover member having an enclosing function and other space defining functions, so that the height of the product is rather large. Thus, when this piezoelectric component is mounted on a printed circuit board or other substrate, the height of the entire device is rather high, so that it is not a surface mounting structure suitable for achieving a reduction in height. Further, since the thickness of the piezoelectric resonator differs depending on the specifications such as resonance frequency, it is difficult to achieve a uniform height dimension of such components.